The husband whose drunken wife killed herself and seven other people in a horrific Taconic State Parkway crash two years ago is now suing the state — and his brother-in-law whose three daughters were among the victims.

Daniel Schuler’s case against the state claims the highway was poorly designed and lacked signs that allowed his wife Diane to drive the wrong way into traffic.

The suit, filed yesterday in the New York Court of Claims, is on behalf of the estate of the Schulers’ two children, Erin, 2, who died, and Bryan, 5, the sole survivor of the worst Westchester crash in 75 years.

He argues that because Hance owned the car that Diane was driving, he is “vicariously liable.”

“As the attorney representing Bryan and Erin Schuler, I’m doing what needs to be done to protect their legal interests at this time,” Kevin Greenan said.

The suits seek unspecified money damages.

The suits shocked a private detective, Thomas Ruskin, hired by Daniel Schuler to look into the crash.

“It’s a terrible tragedy. His wife was drunk and high at the time of the accident that killed seven innocent people. You don’t keep suing people,” Ruskin said.

“If she was alive today, Diane would likely be in jail,” he added.

The suits had to be filed before today, the second anniversary of the crash, he said.

Schuler has repeatedly contested accounts of his wife’s intoxication.

She crashed, going 85 mph, into a Chevrolet Trailblazer, also killing Michael Bastardi Sr., his son Guy Bastardi and a family friend, Daniel Longo.

Word of the lawsuits came as HBO aired a documentary on the tragedy last night.

Michael Bastardi Jr., the son of one of the victims, said he didn’t expect the show to reveal any new details and was upset that it could portray Diane Schuler in a positive light.

“It’s almost impossible to live with losing them and still have to listen to people talk about how she was the perfect mother,” Bastardi told the Westchester Journal News.

Also, Jackie Hance, the wife of Warren Hance and the mother who lost her three daughters in the crash, broke her silence in a Ladies Home Journal article this month.

“People always ask how I feel about Diane,” said Hance, 40, of Floral Park, LI. “You can’t imagine how complex that question is. How does a person go from being like a sister to me — adored by my girls and cherished by my husband — to being the one who ruined our lives?”